1. Field of the Invention
The present invention relates broadly to devices, apparatuses, systems, methods, and techniques for combining light from two or more optical fibers onto a single optical fiber. More particularly, the present invention concerns an apparatus and method for combining light signals carried on two or more input optical fibers onto a single receiving optical fiber. A plurality of fiber-lens arrangements, each comprising an input fiber, a collimating lens, and a focusing lens, are oriented along optic axes that are inclined relative to the receiving fiber, with the inclination angle depending at least in part on the input fibers' numerical aperture and the focal lengths and diameters of the collimating and focusing lenses.
2. Description of the Prior Art
It is often desirable to combine light signals carried on two or more input optical fibers onto a single receiving optical fiber of the same type and diameter. Various techniques are known in the prior art for combining light signals, with some relying, for example, on complex lens arrangements and others relying on light deflecting/transmitting assemblies using fibers of different diameters and numerical apertures. None accomplish the desired combination efficiently, however, in part because the light exiting the input fibers is divergent with an included angle of approximately 25° (corresponding to a standard fiber numerical aperture of 0.22). Thus, these prior art techniques are undesirably inefficient, preserving only a small percentage of the light of the light signals. Furthermore, apparatuses implementing these prior art techniques typically occupy or otherwise require an undesirably large amount of space, thereby prohibiting their use in space-limited applications.
Due to the above-identified and other problems and disadvantages in the prior art, a need exists for an improved apparatus for and method of combining light signals from multiple fibers onto a single receiving fiber.